1. Field of the Invention
The invention concerns headwear for covering the head, such as a hat or cap, including means for controlling the temperature of the head of the wearer. The headwear preferably includes coolant means in a specially constructed receptacle which prolongs the cooling effect.
2. Description of the Related Art
It is well known to provide pockets or enclosures in head gear for insertion of cooling materials. For example, U.S. Pat. No. 2,335,630 discloses a hat structure including a container adapted to receive dry ice or other refrigerant material.
U.S. Pat. No. 3,070,803 discloses a hat including a flexible water-impervious bag formed as part of the crown, the bag provided with an opening to allow the bag to receive and store a coolant in the form of a liquid or ice.
U.S. Pat. No. 3,090,045 teaches a thermal head appliance designed for holding a bag of ice in position on top of the wearer's head.
U.S. Pat. No. 4,484,363 teaches a hat in combination with a cooling device which is removably mounted to the front inside portion of the hat, the device including an enclosure defined by an inverted pocket adapted to receive and store a sealed container filled with a coolant to provide a cooling effect to the forehead and frontal portion of the wearer's head.
U.S. Pat. No. 5,054,122 teaches a hat with a cooling system for the head, the hat including a channel holder on its internal wall surface for receiving a plurality of cooling elements and a flexible, ventilating socket.
U.S. Pat. No. 5,197,292 discloses a headwear device comprising a hat having at least one chamber having a surface capable of transmission of fluid from the chamber to the interior surface of the cap. Melted ice water is permitted to travel to the scalp for cooling of the head.
U.S. Pat. No. 4,815,144 teaches a cap including a cooling pouch which contains a freezable liquid or gel inserted in the forehead area of the cap. The cooling pouch is formed to conform to the shape of the wearer's forehead and a plastic drain channel is provided to catch and retain any condensate which may form on the cooling pouch during periods of high humidity.
One problem with each of the above devices is that the cooling effect provided by the headgear is not sustained for a long period of time, particularly in high-heat conditions such as when repairing the roof of a building.
A further disadvantage of the above devices is that water condensation tends to form in the areas of the hat containing the coolant material, particularly during conditions of high humidity. This condensation represents an absorption of latent energy of atmospheric water vapor as the vapor is condensed into water. This absorption of energy from the atmosphere means that the coolant means is working to cool the atmosphere rather than the wearer, and thus means that (1) the cooling effect of the coolant means is not transmitted entirely to the wearer, and (2) the cooling means more rapidly warms to ambient temperature, so that the cooling effect is abbreviated.
A further problem with the prior art devices is that they may be adapted to receiving coolant means for cooling the head of the wearer when worn in high temperature conditions, but the same hat can not be used to receive heating means to heat the head of the wearer in low temperature conditions.